A conventional display support device, as disclosed in Taiwanese Utility Model Patent No. M393137, includes a hanging arm having a pivot end portion and a movable end portion opposite to the pivot end portion for mounting a display, and a pressure cylinder disposed in the hanging arm. The pressure cylinder is capable of providing a buffer force against the loads exerting thereon. To dispose the display mounted on the movable end portion at a desired position, an external force will be provided to move the hanging arm. After the display is moved to the desired position, the external force is released from the hanging arm. However, the buffer force from the pressure cylinder of the conventional display support device would make the hanging arm to pivot again, thereby causing the display to move away from the desired position.